Princess Cut Diamonds

If the round brilliant is the classic, the princess is the modern answer to it. It keeps the fire and the flash, then squares off the outline into something sharper and more architectural. On the hand it reads as clean and deliberate rather than traditional, which is exactly why it has stayed one of the most requested square shapes for engagement rings since the 1980s.

The princess belongs to the brilliant family of faceting styles, not the step-cut family. The International Gem Society separates these two approaches clearly, and the distinction explains everything about how a princess behaves: brilliant faceting scatters light into rapid white and coloured flashes, while step cutting produces long, calm reflections. A princess sparkles like a round. An Asscher, despite also being square, does not.

A princess cut is a square modified brilliant, normally carrying between 57 and 76 facets depending on how the cutter arranges the pavilion chevrons. Viewed from above it is square or very slightly rectangular. Viewed from the side it is deep, with a sharply tapering pavilion that pulls light down into the stone and throws it back through the table.

That depth is the key to understanding the shape. A princess carries more of its weight below the girdle than a round does, so a one carat princess looks slightly smaller face-up than a one carat round. You are not losing anything; the weight is simply in a different place. It is also what gives the cut its intensity, because light has further to travel and more angles to bounce off before it returns to your eye.

Look for a length-to-width ratio between 1.00 and 1.05 if you want it to read as a true square. Push beyond about 1.10 and the eye starts to see a rectangle, which is a perfectly good look but a different one.

The princess is a young shape. Its direct ancestor is the profile cut, developed in London in 1961 by Arpad Nagy, which first applied brilliant-style faceting to a square outline. The modern princess as we know it was refined around 1980 by Betzalel Ambar, Israel Itzkowitz and Ygal Perlman, who worked out the chevron pavilion arrangement that gives the cut its distinctive crushed-ice sparkle.

It arrived at exactly the right moment. The 1980s wanted cleaner, squarer lines than the ornate settings of previous decades, and the princess delivered them without asking anyone to give up brilliance. Four decades later it still looks contemporary, which is a rare thing for a design born in a specific era.

Princess cuts are not given a standard cut grade the way round brilliants are, so you have to read the proportions instead of trusting a single letter. Depth between roughly 65% and 75% with a table around 65% to 75% tends to produce the liveliest stone. Too shallow and the centre goes flat and glassy; too deep and the stone looks small for its weight and darkens in the middle.

Symmetry matters more here than on most shapes. The four corners should be even and the chevrons should mirror each other cleanly, because any misalignment shows immediately in a square outline. If you want to understand what cut quality is doing to a stone before you compare princess proportions, start with our guide to diamond cut.

A princess concentrates colour at its four points. In a warm-tinted stone the corners will look noticeably deeper than the centre, and once you have seen it you cannot unsee it. This is the main practical reason to stay high on the colour scale with this shape rather than economising the way you might with a round.

Every Ronora princess sits in the D-E-F colourless range, so the corners stay as bright as the table. We do not stock G or below in any shape.

This is where the princess rewards you. All that brilliant faceting breaks light up so rapidly that small inclusions disappear into the sparkle, in a way they never would inside an emerald cut. The one thing worth checking is that nothing sits near a corner, since an inclusion there is both more visible and a genuine durability risk when the stone is being set.

Ronora princess cuts are VVS1, VVS2 or VS1 clarity, which sits comfortably above the point where anything becomes visible to the eye. Each diamond of one carat or more ships with its own IGI certificate, so you can see exactly where any inclusions sit on the plot before you commit.

A one carat princess measures roughly 5.5mm across, against about 6.5mm for a one carat round. That sounds like a loss until you account for the corners: a square fills more of the finger's width than a circle drawn inside it, so the two read much closer on the hand than the millimetre figures suggest. Our diamond measurements guide draws both at true size so you can judge it yourself.

The princess also wastes very little rough. A round brilliant throws away well over half the original crystal, while a princess follows the natural octahedral form of the rough closely and keeps far more of it. Less waste has always meant a lower price per carat, and with lab grown stones that advantage stacks on top of an already lower starting point.

See a princess cut at actual size on your own ring size, or as a stud or pendant, with Find Me Diamond, our free diamond size visualizer.

Every good princess setting solves the same problem: the corners. They are the thinnest part of the stone and they sit exactly where a ring catches on things. Protect them and a princess wears beautifully for decades.

• V-prong solitaire. The standard answer, and the best one. A V-shaped prong wraps each corner completely instead of gripping it from one side. Clean, modern, and genuinely protective.
• Halo. A frame of small round diamonds guards all four corners while making the centre stone read noticeably larger. It also squares off visually into a slightly softer outline, which suits people who find a bare princess too severe.
• Channel set. Smaller princess stones sit shoulder to shoulder inside a metal channel with no prongs at all. Nothing protrudes, which makes it the most practical choice for daily wear.
• Pavé split shank. Fine pavé along a divided band draws the eye up to the square centre and adds sparkle without competing with it.
• Three stone. A princess centre with tapered baguettes or smaller princess sides gives a strongly geometric, Art Deco line.

What it does well

• The most brilliant of all the square shapes, by a clear margin.
• More carat for your budget, because so little of the rough is wasted.
• Hides small inclusions far better than any step cut.
• Looks modern and architectural without looking like a trend.
• Works with almost any band, from plain solid gold to full pavé.

What to watch

• The corners chip if they are not protected. Insist on V-prongs, a bezel or a halo.
• Colour pools at the points, so a warm-tinted stone gives itself away.
• Face-up spread is smaller than a round of the same carat weight.
• No universal cut grade exists, so proportions have to be read individually.